Energy from wind can be harnessed in several forms. It could be used to run turbines and hence produce electricity, provide mechanical power, run wind pumps, propel sails or could be simply just used for drying or husk separation in agriculture. The most common, widespread and perhaps economically significant among these is the use of wind energy to produce power in wind farms. Wind energy is progressively being used as a means to reduce the dependency on non-renewable energy sources. Furthermore, its use can be advocated as it comes with no environmental pollution and is not likely to ever run out. 
A number of studies have been done to evaluate the global potential of wind energy, which is estimated at 500,000 TWh/year.  This estimate was calculated using average wind speeds of over 5 m/s at an altitude of 10 m above the ground level. Excluding the land under any form of cultivation from these numbers, a more conservative estimate of about 20,000 TWh/year in global potential of wind energy is obtained. 
Even though the potential of wind power is enormous in several regions of the world as seen above, it is not being tapped anywhere close to the extent to which it can. Africa, for example, has an installed capacity of about 752 MW (2008), primarily in northern parts of the continent, with Egypt, Tunisia and Morocco being the major contributors to this number.  Northern America has a total installed capacity of wind power of about 27,254 MW as of 2009.  The United States, being the pioneer in the industrial use of wind power since its first production in wind farms in 1981 in California, had a capacity of about 10 GW in 2009. The southern region of the continent, however, has much smaller capacity. The Latin Americas, combined together have an installed capacity of 670 MW as of 2009.  Australia and the Oceania region have installed capacities of about 2.8 GW.  The greatest contribution in this number comes from Australia and New Zealand. Asia has great potential for wind energy development although a considerable amount of such land is inaccessible. Wind energy development in Asia was initiated by India which had an installed capacity of 10.9 GW as of 2009.  China was soon to catch up and currently is the largest producer of energy from wind with installed capacities which increased from about 12 GW in 2008 to 13.8 GW in 2009.  Other regions of Asia where wind power is significant are countries like Japan, South Korea, Taiwan and the Philippines, which have a total capacity of 2.9 GW as of 2009.  Europe is the global leader in wind energy production with an installed capacity of 63.8 GW.  There is a great push in countries such as Germany, France and Denmark, in the forms of government regulations, to promote the use of renewable energy sources as means of electricity production. Leaders here are Spain (2.5 GW), Germany (1.9 GW), Italy, France and the UK (all three with capacities of about 1 GW). 
There are several impacts which arise from the use of wind power, primarily with using large scale wind farms. Some of these are discussed below:
Noise: Wind turbines produce significant noise in the area they operate due to the mechanical motions in the gear box or the rotation of the turbine blades. A medium sized 250 kW wind turbine inhibits human habilitation within 200-300 m from itself due to the noise levels generated. 
Safety: Another reason which limits habilitation near wind farms is that of safety itself. Objects such as blade fragments or settled ice can be thrown several meters away and hence further limit land use in wind farm proximity (of around 300-400 m) for human settlements for safety reasons.
Land Required: One criticism of wind energy use is the apparent wastage of land for wind farms. Assuming an energy production capacity of 4MW/km2, a land area of about 1200 km2 is required to output 1.7 GW of power.  Land used for wind farms could be put to better use by using it for agriculture.
Wind energy is a good clean alternative to producing energy from fossil fuels. There is great potential for this form of energy throughout the world and its use is gradually increasing. Although there are several problems associated with its use, significant research is being done so as to decrease its negative impacts on the environment and society.
© Misam Jaffer. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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